2-1/2" hole saw. High-speed steel cutting edge welded to alloy steel body. Cuts material up to 1-3/4" deep. Will cut through a 2x4. Use for cutting in aluminum, brass, bronze, copper, plastic, stainless steel, wood, and other compositions. Sizes from 3/4" to 6". Use DeWALT mandrel model Nos. as indicated. 2-1/2", model Nos. DW1802, DW1803, DW1804 & DW1818